Antenna system for dual mode satellite/cellular portable phone

ABSTRACT

An antenna operable in two disparate frequency bands is disclosed as including a first quadrifilar helix having four conductive elements arranged helically to define a cylinder of substantially constant radius, where the first quadrifilar helix is formed of two bifilar helices arranged orthogonally and excited in phase quadrature. A quadrature feed network is connected to the first quadrifilar helix, wherein one end of a coupling element thereof is connected to a first end of each conductive element. The quadrature feed network also includes a first feedpoint for operation of the antenna with circular polarization in a first frequency band and a second feedpoint for operation of the antenna with linear polarization in a second frequency band. The antenna may include a second quadrifilar helix connected to the quadrature feed network and having four conductive elements arranged helically to define a cylinder of substantially constant radius, where the second quadrifilar helix is formed by two bifilar helices arranged orthogonally and excited in phase quadrature. The second quadrifilar helix is wound in opposite sense with respect to the first quadrifilar helix so as to be conductively coupled therewith.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a dual modesatellite/cellular portable phone and, in particular, to an antennasystem for a dual mode satellite/cellular portable phone.

2. Description of Related Art

Portable cellular phones are well known and have been utilized for thepast several years. Such cellular phones typically transmit and receivesignals at a frequency of approximately 800-950 Megahertz by means of anantenna designed for such purpose. Recently, however, it has becomedesirable for a second mode of communication, (e.g., satellite) to beemployed in areas where cellular towers or stations are not available.Satellite communication occurs at frequencies much higher than forcellular communication (typically 1.0-3.0 Gigahertz) and likewiserequires an antenna specifically designed for such communication. Itwill be understood that there are certain differences between an antennautilized for cellular communication versus one utilized for satellitecommunication. One example is that the cellular antenna will preferablybe linearly polarized so as to function as a monopole while thesatellite antenna is circularly polarized in order to providehemispherical coverage. A further distinction is that communication inthe satellite mode involves a directional component (where link marginis increased when the satellite antenna is pointed toward thesatellite), whereas communication in the cellular mode does not.

Because at least some of the characteristics desirable for the cellularand satellite antennas are inconsistent, one approach that has beentaken is the antenna system shown and disclosed in a patent applicationentitled "Antenna System For Dual Mode Satellite/Cellular PortablePhone," Ser. No. 08/586,433, also filed by the assignee of the presentinvention. As seen therein, separate antennas were provided with aportable phone for cellular and satellite communication. While theantenna system disclosed by this patent application is adequate for itsintended purpose, it will be noted that an antenna system having only asingle antenna which can be utilized for both cellular and satellitemodes of communication would be preferred from the standpoints of costand aesthetics.

In light of the foregoing, a primary objective of the present inventionis to provide an antenna system for a portable phone which enables thetransmission and receipt of signals in both cellular and satellite modesof communication.

Another object of the present invention is to provide an antenna systemfor a dual mode satellite/cellular portable phone which includes only asingle antenna for transmitting and receiving signals in cellular andsatellite modes of communication.

A further object of the present invention is to provide an antennasystem for a dual mode satellite/cellular portable phone which ismounted so as to enable better link margin with respect to an applicablesatellite.

Yet another object of the present invention is to provide an antennasystem for a dual mode satellite/cellular portable phone which minimizesthe need for manipulation by the user thereof.

Still another object of the present invention is to provide an antennasystem for a dual mode satellite/cellular portable phone which isaesthetically pleasing to the user thereof.

Another object of the present invention is to provide an antenna systemfor a dual mode satellite/cellular portable phone which minimizes theoverall impact on size of the portable phone.

A still further object of the present invention is to provide an antennasystem for a dual mode satellite/cellular portable phone which permitsthe use of separate frequency sub-bands for transmitting and receivingsignals within the satellite and cellular modes of communication.

These objects and other features of the present invention will becomemore readily apparent upon reference to the following description whentaken in conjunction with following drawing.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, an antennaoperable in two disparate frequency bands is disclosed as including afirst quadrifilar helix having four conductive elements arrangedhelically to define a cylinder of substantially constant radius, wherethe first quadrifilar helix is formed of two bifilar helices arrangedorthogonally and excited in phase quadrature. A quadrature feed networkis connected to the first quadrifilar helix, wherein one end of acoupling element thereof is connected to a first end of each conductiveelement. The quadrature feed network also includes a first feedpoint foroperation of the antenna with circular polarization in a first frequencyband and a second feedpoint for operation of the antenna with linearpolarization in a second frequency band. The antenna may include asecond quadrifilar helix connected to the quadrature feed network andhaving four conductive elements arranged helically to define a cylinderof substantially constant radius, where the second quadrifilar helix isformed by two bifilar helices arranged orthogonally and excited in phasequadrature. The second quadrifilar helix is wound in opposite sense withrespect to the first quadrifilar helix so as to be electromagneticallydecoupled therefrom.

In accordance with a second aspect of the present invention, an antennafor transmitting and receiving signals within a first frequency band anda second frequency band is disclosed as including a flexible sheet offilm having a first side and a second side, a first metallized patternformed on the first side of the film sheet having a plurality of spiralarms connected to a coupler, and a second metallized pattern formed onthe second side of the film sheet having a plurality of spiral armsconnected to a coupler. The film sheet is formed into a cylindrical tubehaving a longitudinal axis therethrough so that a first coaxialquadrifilar helix is constructed by the spiral arms of the firstmetallized pattern and a second coaxial quadrifilar helix is constructedby the spiral arms of the second metallized pattern, with the first andsecond quadrifilar helices being wound in an opposite sense to avoidelectromagnetic coupling therebetween.

In accordance with a third aspect of the present invention, a portablephone having RF circuitry contained within a main housing for operatingthe portable phone in both cellular and satellite modes is disclosed.More specifically, an antenna assembly for such portable phone isdisclosed as including a base member connected to the main housing ofthe portable phone and a radome member rotatably connected to the basemember, where the radome member contains therein a printed antenna whichis able to transmit and receive signals in the cellular and satellitemodes of operation. The antenna assembly may also include a hinge memberrotatable within the base member, wherein the radome member is connectedat one end of such hinge member so as to be rotatable about an axisbetween a first position adjacent a side surface of the main housing anda second position. Additionally, an elbow member is preferably connectedto the hinge member at a first end and the radome member at a second endso that the hinge and radome members are substantially perpendicular inorientation.

In accordance with a fourth aspect of the present invention, aquadrifilar helix antenna is disclosed as including a flexible sheet ofdielectric film with first and second pairs of conductive arms printedupon the flexible sheet of dielectric film in such manner that theconductive arms form a quadrifilar helix when the flexible sheet isrolled into a cylindrical tube. A balanced 90° branch line coupler isalso printed on the flexible sheet of dielectric film, wherein thecoupler is able to provide two balanced output signals in phasequadrature relative to each other. The coupler further includes a firstoutput port connected to the first pair of conductive arms which has afirst terminal for providing an in-phase portion of a first outputsignal to one of the first pair of conductive arms and a second terminalfor providing an anti-phase portion of the first output signal to theother of the first pair of conductive arms. The coupler also includes asecond output port connected to the second pair of conductive arms inwhich the second output port has a first terminal for providing anin-phase portion of a second output signal to one of the second pair ofconductive arms and a second terminal for providing an anti-phaseportion of the second output signal to the other of the second pair ofconductive arms. The coupler has at least one input port for receivingan input signal and splitting the input signal between the first andsecond pairs of conductive arms in relative phase progression so as tobe radiated with circular wave polarization.

BRIEF DESCRIPTION OF THE DRAWING

While the specification concludes with claims particularly pointing outand distinctly claiming the present invention, it is believed the samewill be better understood from the following description taken inconjunction with the accompanying drawing in which:

FIG. 1 is a perspective view of a handheld portable phone operable inboth satellite and cellular modes of communication including the antennaassembly of the present invention, where the radome member of theantenna assembly is in a first position;

FIG. 2 is a perspective view of the handheld portable phone depicted inFIG. 1, where the radome member of the antenna assembly is in a secondposition;

FIG. 3 is an exploded, perspective view of the antenna assembly with theportable phone depicted in FIGS. 1 and 2;

FIG. 4 is a bottom perspective view of the base member for the antennaassembly depicted in FIGS. 1-3;

FIG. 5 is a planar front view of a first embodiment for the printedantenna located within the radome member of the antenna assemblydepicted in FIGS. 1-3;

FIG. 6 is a planar rear view of the printed antenna depicted in FIG. 5;

FIG. 7 is a front view of the printed antenna depicted in FIGS. 5 and 6after being formed into a cylindrical tube configuration, whereelectrical elements associated with the various feedpoints of theantenna are schematically depicted;

FIG. 8 is a planar front view of a second embodiment for the printedantenna located within the radome member of the antenna assemblydepicted in FIGS. 1-3, where electrical elements associated with thevarious feedpoints of the antenna are schematically depicted;

FIG. 9 is a planar rear view of the printed antenna depicted in FIG. 8,where the electrical elements associated with the various feedpoints ofthe antenna are also schematically depicted; and

FIG. 10 is a front view of the printed antenna depicted in FIGS. 8 and 9after being formed into a cylindrical tube configuration.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawing in detail, wherein identical numeralsindicate the same elements throughout the figures, FIG. 1 depicts ahandheld portable phone 10 which is operable in the dual modes ofsatellite and cellular communication. It will be seen that portablephone 10 has a main housing 12 and preferably an antenna assembly 14 inaccordance with the present invention which transmits and receivessignals within certain specified frequency bands of operation. A keypad16, display 18, and speaker 20 are provided along a front surface 22 ofmain housing 12 to permit a user to operate portable phone 10 in thenormal manner. Of course, it will be understood that main housing 12 hasRF circuitry located therein enabling portable phone 10 to communicatein both the cellular and satellite modes of communication. While notshown, exemplary RF circuitry is shown and described in a patentapplication entitled "Dual Mode Satellite/Cellular Terminal," Ser, No.08/501,575, which is owned by the assignee of the present invention andis hereby incorporated by reference.

With respect to antenna assembly 14, it will be noted from FIGS. 1 and 2that it preferably is located adjacent to a top surface 24 (see FIG. 3)and one side surface 26 of main housing 12 and therefore has asubstantially L-shaped configuration (although it could just as easilybe located along the other side of main housing 12). Antenna assembly 14is preferably detachably secured to main housing 12 and includes a basemember 28 connecting antenna assembly 14 to main housing 12, a radomemember 30 containing a printed antenna 32 therein (to be discussed ingreater detail hereinafter), a hinge member 34 which enables radomemember 30 to rotate about an axis 36 between a first position adjacentside surface 26 (shown in FIG. 1) to a second position substantially180° from the first position (shown in FIG. 2), and an elbow member 38which connects radome member 30 to hinge member 34 and rotates aboutaxis 36 in conjunction with radome member 30. It will be understood thatradome member 30 is maintained in the first position when it is not inuse or in a standby mode to minimize the overall size of portable phone10, as antenna assembly 14 will slightly increase the overall height andwidth of portable phone 10 from that of main housing 12. In this firstposition, the impact on ease of holding and transporting portable phone10 is minimized. Otherwise, radome member 30 and elbow member 38 ofantenna assembly 14 are rotated to the second position when used totransmit or receive signals.

As indicated hereinabove, antenna assembly 14 preferably is detachablymounted to main housing 12 by means of base member 28. Accordingly, basemember 28 may be constructed similarly to a support bracket assemblyused to detachably mount a flip cover to the main housing of a portablephone shown and described in a patent application entitled "DetachableFlip Cover Assembly For A Portable Phone," Ser. No. 08/586,434, which isowned by the assignee of the present invention and is herebyincorporated by reference. Thus, as shown in FIGS. 3 and 4, base member28 preferably includes a first slotted portion 40 which is sized toreceive top surface 24 and a portion of main housing 12. A latchingmechanism, preferably in the form of a detent 42 which is positioned tobe received in a recess (not shown) in a rear surface of main housing12, is provided to couple base member 28 to main housing 12. In order tofacilitate the mounting of base member 28 to main housing 12, firstslotted portion 40 of base member 28 preferably has at least one guidepin 44 positioned therein which is received within a correspondingopening 46 in main housing 12, as well as a dovetail-type guide locatedon at least one of main housing side surfaces 26 and 50. Eachdovetail-type guide includes a male member 52 located within firstslotted portion 40 of base member 28 and a complementary female member54 associated with main housing 12. Connectors 56, 58, and 60 arelocated within first slotted portion 40 of base member 28 and connectedto one end of coaxial cables 62, 64, and 66, respectively, with theother end of coaxial cables 62, 64, and 66 being connected to printedantenna 32. Complementing this arrangement, connectors 68, 70, and 72are coupled to the internal RF circuitry and extend from top surface 24of main housing 12 so as to be aligned with and mated to connectors 56,58, and 60 when base member 28 is mounted to main housing 12. In thisway, the RF circuitry of portable phone 10 is properly connected toprinted antenna 32 of antenna assembly 14.

Base member 28 further includes a second slotted portion 74 oppositefirst slotted portion 40, where hinge member 34 of antenna assembly 14is rotatably mounted thereto. In this way, portable phone 10 permitsflexibility in the positioning of printed antenna 32 by a user thereof,whereby the signal strength is maximized (when in the satellite mode ofcommunication) by pointing printed antenna 32 toward an applicablesatellite. More specifically, hinge member 34 includes a rotary jointshaft 76 that extends through a pair of rotary joint bearings 78 and 80positioned within grooved slots 79 and 81, respectively, immediately tothe interior of end walls 82 and 84 of base member 28. It will be notedthat rotary joint shaft 76, as well as rotary joint bearings 78 and 80,preferably has a D-shaped cross-section in order to prevent radomemember 30 of antenna assembly 14 from over-rotating about axis 36 (thepreferred range of rotation being approximately 180° in one direction orthe other). One end of rotary joint shaft 76 is preferably retained toelbow member 38 of antenna assembly 14 while the other end preferablyhas a swivel cap attached thereto (not shown). As seen in FIG. 3, aremovable covering 88 optionally is secured to base member 28 in orderto protect hinge member 34 from dirt and other contaminants.

Elbow member 38 of antenna assembly 14 has rotary joint shaft 76connected thereto at a first end 90 and radome member 30 connected at asecond end 92 (which generally will be oriented substantially 90° withrespect to first end 90). As seen in FIG. 3, elbow portion 38 is hollowand includes a side opening 94 therein which is covered by a removableaccess cap 96. Preferably, access cap 96 is frictionally retained toelbow member 38, such as by a male-female configuration (a plurality offemale portions 97 being seen in FIG. 3). Likewise, radome member 30 maybe secured to second end 92 of elbow member 38 by means of a frictionfit. In this regard, FIG. 3 depicts radome member 30 as beingsubstantially a cylindrical tube having an inner radius R₁ slightlygreater than an outer radius R₂ of cylindrical second end 92 of elbowmember 38, where radome member 30 is able to slide over such cylindricalsecond end 92 until it is seated against a lip 98.

It will be understood that the hollow nature of both rotary joint shaft76 and elbow member 38 enables coaxial cables 62, 64 and 66 to beconnected to printed antenna 32 in radome member 30 at one end and toconnectors 56, 58 and 60 at the other end by means of openings (notshown) in rotary joint shaft 76. In particular, signals transmitted toan applicable satellite via printed antenna 32 are sent from the RFcircuitry in main housing 12 through coaxial cable 62, signals receivedby printed antenna 32 from an applicable satellite are sent to the RFcircuitry in main housing 12 through coaxial cable 64, and coaxial cable66 is utilized to both transmit signals to and receive signals fromprinted antenna 32 when portable phone 10 is in the cellular (monopole)communication mode. In order to maintain coaxial cables 62, 64, and 66in the proper shape, as well as produce a minimum bend radius, preventchafing of the cables and reduce fatigue failures of the jacket materialunder flexing conditions, it is preferred that the outer jackets thereofbe heat formed as described in a patent application entitled "CoaxialCable Assembly For A Portable Phone," Ser. No. 08/613,700, which is alsoowned by the assignee of the present invention and hereby incorporatedby reference.

With respect to radome member 30 of antenna assembly 14, it has beennoted that a printed antenna 32 preferably is located therein. Althoughprinted antenna 32 is rolled into a cylindrical tube to be in thedesired shape for radome member 30 (as seen in FIG. 7), it will be bestunderstood by referring to the planar top and rear views thereof inFIGS. 5 and 6. As seen therein, printed antenna 32 preferably isconstructed of a flexible film sheet 100 made of a dielectric material(e.g., mylar, fiberglass, kevlar, or the like). Film sheet 100 has afront surface 102 with a metallized layer 104 applied thereto in adesired pattern (see FIG. 5) and a rear surface 106 with a secondmetallized pattern 108 applied thereto of a predetermined design (seeFIG. 6). More particularly, front metallized layer 104 has a pair ofspiral arms 105 and 107 and rear metallized layer 108 has a pair ofspiral arms 109 and 111 which are configured so that printed antenna 32has a quadrifilar helix design when film sheet 100 is rolled into acylindrical tube, as best seen in FIG. 7. It will be understood thatfront and rear metallized layers 104 and 108 are preferably printed onfilm sheet 100, with the dimensions thereof being photographicallyreproduced. Spiral arms 105, 107, 109, and 111, for their part,typically will have a length substantially equivalent to either aquarter wavelength or a three-quarter wavelength of the desiredfrequencies of operation.

It will be further understood that the cylindrical tube into which filmsheet 100 is rolled preferably has a controlled diameter D (see FIG. 7).One approach for performing this task is to wrap film sheet 100 about amandrel and glue the overlapping portions which extend more than 360°.The mandrel would then be removed once the glue has dried. By so formingfilm sheet 100, it will be seen that a quadrifilar helix 101 is formedby spiral arms 105, 107, 109 and 111 since they are wound in the samesense.

A balanced 90° branch line coupler 110, made by printed patterns onfront and rear metallized layers 104 and 108, is preferably used toprovide the four-phase drive signals to spiral arms 105, 107, 109, and111 of printed antenna 32. It will be understood that coupler 110 is anadaptation of an unbalanced branch line coupler described in U.S. Pat.No. 4,127,831 to Riblet. Instead of the unbalanced form in Riblet wherea branch line coupler pattern is printed on one side of a dielectriclayer with a ground plane on the other side thereof, coupler 110 of thepresent invention includes two identical coupler patterns placedback-to-back on front and back surfaces 102 and 106 of dielectric filmsheet 100. Coupler 110 thus has a balanced construction in which squareconductors 112 (front metallized layer 104) and 114 (rear metallizedlayer 108) are separated by dielectric film sheet 100. Of course,coupler 110 provides the connection between printed antenna 32 andcoaxial cables 62, 64, and 66 so that printed antenna 32 is connected tothe RF circuitry in portable phone 10.

It will be noted from FIGS. 5 and 6 that spiral arms 105 and 111 areconnected to a first output of coupler 110 made up of upper legs 113 and119 extending from square conductors 112 and 114, respectively.Likewise, spiral arms 107 and 109 are connected to a second output ofcoupler 110 formed by upper legs 115 and 117 extending from squareconductors 112 and 114, respectively. In this way, upper legs 113 and115 will carry the in-phase portion and upper legs 117 and 119 willcarry the anti-phase portion of the output signal from coupler 110. Itwill further be seen from FIG. 7 that coupler 110 has a first input port116 including lower legs 118 and 120 of square conductors 112 and 114,respectively, which printed antenna 32 uses for transmitting frequencyf₁ and receiving frequency f₂ while in the satellite mode ofcommunication (coupler 110 being balanced and quadrifilar helix 101having circular polarization) and a second input port 122 includinglower legs 124 and 126 of square conductors 112 and 114, respectively,which printed antenna 32 uses for frequency f₃ (both transmitting andreceiving) while in the cellular or monopole mode of communication(coupler 110 being unbalanced and quadrifilar helix 101 having linearpolarization).

More specifically, it will be seen in FIG. 7 that a dummy load 128 isprovided across lower legs 124 and 126 of second input port 122 in orderto terminate the balanced mode of coupler 110 at second input port 122.In this way, only satellite frequencies f₁ and f₂ are able to be usedduring the balanced mode of coupler 110 since their feedpoint 129 isattached to first input port 116. A short circuit 130 is providedbetween front and rear metallized layers 104 and 108 in order to placecoupler 110 in an unbalanced mode, with feedpoint 131 being utilized forcellular frequency f₃. Short circuit 130 preferably is locatedapproximately a quarter-wavelength away from dummy load 128 so that itappears as an open circuit.

A second embodiment for the printed antenna, designated by the numeral132, is depicted in FIGS. 8-10. As explained hereinabove with respect toprinted antenna 32, a flexible film sheet 134 is provided in which afirst metallized layer 136 is applied to a front surface 138 thereof anda second metallized layer 140 is applied to a rear surface 142. A firstpair of spiral arms 143 and 144 are provided in accordance withmetallized layer 136 and connected to upper legs 156 and 158 of acoupler 165 like that previously described. Spiral arms 143 and 144 arein substantially parallel relation as they extend from upper legs 156and 158. After traveling a distance d₁, spiral arm 143 has a spiral arm145 branch off therefrom substantially perpendicular thereto and spiralarm 144 likewise has a spiral arm 146 branch off substantiallyperpendicular thereto. It will be seen from FIGS. 8 and 9 that spiralarm 143 continues along front surface 138 of film sheet 134 while spiralarm 144 enters a plated via 166 and thereafter extends in the samedirection along rear surface 142 of film sheet 134.

A second set of spiral arms 149 and 150 are provided by metallized layer140 and connected to upper legs 160 and 162 of coupler 165. Spiral arms149 and 150 are oriented substantially parallel to each other as theyextend from upper legs 160 and 162. After traveling a distance d₂,spiral arm 149 has a spiral arm 151 branch off substantiallyperpendicular thereto. It will be seen that spiral arm 149 enters aplated via 167 so that spiral arm 151 travels along front surface 138 offilm sheet 134 until it passes spiral arm 150, after which spiral arm151 enters another plated via 168 and extends along rear surface 142 offilm sheet 134. It will also be seen that a spiral arm 152 branches offsubstantially perpendicularly from spiral arm 150. Accordingly, spiralarms 150 and 152 extend along rear surface 142 of film sheet 134 for aspecified length. It will be understood that when film sheet 134 iswrapped into a cylindrical tube configuration, a first quadrifilar helix148 is formed by spiral arms 143, 144, 145, and 146 of front metallizedlayer 136 and a second quadrifilar helix 154 is formed by spiral arms149, 150, 151, and 152. It will be noted that none of the spiral armsfor each quadrifilar helix touch where they cross, which is why platedvias 166, 167, and 168 are strategically provided. This preventselectromagnetic coupling between first and second quadrifilar helices148 and 154. It will also be understood that both first quadrifilarhelix 148 and second quadrifilar helix 154 are coaxial with alongitudinal axis 31 through printed antenna 132, with first quadrifilarhelix 148 being located concentrically outside of second quadrifilarhelix 154.

Since printed antenna 132 has a three-mode configuration, a feedpoint171 for a first satellite frequency band (having a circular polarizationin a given direction) is connected to a first input port 170 of coupler165 and a feedpoint 173 for a second satellite frequency band (having acircular polarization opposite that of the first satellite frequencyband) is connected to a second input port 172 of coupler 165. In thisway, separate frequency bands for transmitting and receiving signals maybe utilized with printed antenna 132. It will be understood that firstquadrifilar helix 148 is preferably adapted to the lower of thefrequency bands and that second quadrifilar helix 154 is adapted to thehigher of the frequency bands (since spiral arms 143, 144, 145 and 146are longer than spiral arms 149, 150, 151, and 152). Of course, coupler165 is in a balanced mode when either the first frequency band or thesecond frequency band are provided to printed antenna 132 in order toprovide circular polarization. By contrast, a third frequency band usedfor transmitting and receiving cellular signals is provided printedantenna 132 when coupler 165 is in an unbalanced mode, where one offirst quadrifilar helix 148 and second quadrifilar helix 154 is linearlypolarized as a monopole and the other acts as a parasitic element.Accordingly, the third frequency band may utilize either first inputport 170 or second input port 172 as its feedpoint 175 (although it isshown as being connected to second input port 172 in FIGS. 8 and 9).

Having shown and described the preferred embodiment of the presentinvention, further adaptations of the antenna assembly described hereincan be accomplished by appropriate modifications by one of ordinaryskill in the art without departing from the scope of the invention.

    ______________________________________                                        PARTS LIST                                                                    ______________________________________                                        10   dual mode satellite/cellular portable phone (generally)                  12   main housing                                                             14   antenna assembly (generally)                                             16   keypad                                                                   18   display                                                                  20   speaker                                                                  22   front surface of main housing                                            24   top surface of main housing                                              26   side surface of main housing                                             28   base member of antenna assembly                                          30   radome member of antenna assembly                                        31   longitudinal axis through radome member                                  32   printed antenna                                                          34   hinge member of antenna assembly                                         36   axis of rotation                                                         38   elbow member of antenna assembly                                         40   first slotted portion of base member                                     42   detent                                                                   44   guide pin(s)                                                             46   opening(s) for receipt of guide pin(s)                                   50   side surface of main housing                                             52   male member of dovetail-type guide                                       54   female member of dovetail-type guide                                     56   coaxial connector                                                        58   coaxial connector                                                        60   coaxial connector                                                        62   coaxial cable for transmitting satellite signals                         64   coaxial cable for receiving satellite signals                            66   coaxial cable for transmitting/receiving cellular signals                68   coaxial connector on main housing                                        70   coaxial connector on main housing                                        72   coaxial connector on main housing                                        74   second slotted portion of base member                                    76   rotary joint shaft                                                       78   rotary joint bearing                                                     79   grooved slot                                                             80   rotary joint bearing                                                     81   grooved slot                                                             82   end wall of base member                                                  84   end wall of base member                                                  88   covering for hinge member                                                90   first end of elbow member                                                92   second end of elbow member                                               94   side opening in elbow member                                             96   access cap to elbow member opening                                       97   female portions of access cap connection                                 98   lip of elbow member                                                      100  flexible dielectric sheet of printed antenna                             101  quadrifilar helix                                                        102  front surface of film sheet                                              104  metallized layer on front surface of film sheet                          105  spiral arm on front metallized layer                                     106  rear surface of film sheet                                               107  spiral arm on front metallized layer                                     108  metallized layer on rear surface of film sheet                           109  spiral arm on rear metallized layer                                      110  coupler                                                                  111  spiral arm on rear metallized layer                                      112  square conductor on front metallized layer                               113  upper leg of square conductor 112                                        114  square conductor on rear metallized layer                                115  upper leg of square conductor 112                                        116  first input port of coupler                                              117  upper leg of square conductor 114                                        118  lower leg of square conductor 112                                        119  upper leg of square conductor 114                                        120  lower leg of square conductor 114                                        122  second input port of coupler                                             124  lower leg of square conductor 112                                        126  lower leg of square conductor 114                                        128  dummy load                                                               129  feedpoint of satellite frequencies                                       130  short circuit                                                            131  feedpoint of cellular frequency                                          132  printed antenna (alternative configuration---three mode)                 134  film sheet                                                               136  metallized layer on front surface                                        138  front surface of film sheet                                              140  metallized layer on rear surface                                         142  rear surface of film sheet                                               143  spiral arm on front metallized layer                                     144  spiral arm on front metallized layer                                     145  spiral arm on front metallized layer                                     146  spiral arm on front metallized layer                                     148  first quadrifilar helix                                                  149  spiral arm on rear metallized layer                                      150  spiral arm on rear metallized layer                                      151  spiral arm on rear metallized layer                                      152  spiral arm on rear metallized layer                                      154  second quadrifilar helix                                                 156  upper leg of coupler (front metallized layer)                            158  upper leg of coupler (front metallized layer)                            160  upper leg of coupler (rear metallized layer)                             162  upper leg of coupler (rear metallized layer)                             165  coupler                                                                  166  plated via                                                               167  plated via                                                               168  plated via                                                               169  via                                                                      170  first port of coupler                                                    171  feedpoint for a first satellite frequency band                           172  second port of coupler                                                   173  feedpoint for a second satellite frequency band                          175  feedpoint for a cellular frequency band                                  R.sub.1                                                                            inner radius of radome member                                            R.sub.2                                                                            outer radius of elbow member second end                                  f.sub.1                                                                            transmit frequency for satellite mode of communication                   f.sub.2                                                                            receive frequency for satellite mode of communication                    f.sub.3                                                                            transmit/receive frequency for cellular mode of communication            ______________________________________                                    

What is claimed is:
 1. An antenna operable in two disparate frequencybands, comprising:(a) a first quadrifilar helix including fourconductive elements arranged helically to define a cylinder ofsubstantially constant radius, said first quadrifilar helix being formedof two bifilar helices arranged orthogonally and excited in phasequadrature; and (b) a quadrature feed network connected to said firstquadrifilar helix, wherein one end of a coupling element thereof isconnected to a first end of each said conductive element, saidquadrature feed network further comprising:(1) a first feedpointconnected to a first pair of said conductive elements, said couplingelement being balanced and said first quadrifilar helix having circularpolarization, wherein said antenna is operable in a first frequencyband; and (2) a second feedpoint connected to a second pair of saidconductive elements, said coupling element being unbalanced and saidfirst quadrifilar helix having linear polarization, wherein said antennais operable in a second frequency band.
 2. The antenna of claim 1,wherein said first frequency band is within a satellite mode ofoperation.
 3. The antenna of claim 2, wherein said antenna is operablein said first frequency band for transmitting a signal and said antennais operable in a third frequency band for receiving a signal.
 4. Theantenna of claim 1, wherein said second frequency band is within acellular mode of operation.
 5. The antenna of claim 4, wherein saidantenna is operable in said second frequency band for transmitting andreceiving a signal.
 6. The antenna of claim 1, said antenna furthercomprising a sheet of dielectric material, wherein said conductiveelements and said coupling element are printed thereon.
 7. The antennaof claim 6, wherein said first pair of said conductive elements areprinted on a first surface of said dielectric sheet and said second pairof said conductive elements are printed on a second surface of saiddielectric sheet.
 8. The antenna of claim 1, further comprising a secondquadrifilar helix connected to said quadrature feed network and havingfour conductive elements arranged helically to define a cylinder ofsubstantially constant radius, said second quadrifilar helix beingformed of two bifilar helices arranged orthogonally and excited in phasequadrature, wherein said second quadrifilar helix is wound in anopposite direction from said first quadrifilar helix with respect to alongitudinal axis for said helices.
 9. The antenna of claim 8, whereinsaid respective conductive elements of said first and second quadrifilarhelices are conductively coupled.
 10. The antenna of claim 8, whereinthe lengths of said conductive elements for said first quadrifilar helixare greater than the lengths of said conductive elements for said secondquadrifilar helix.
 11. The antenna of claim 8, wherein said secondquadrifilar helix is positioned concentrically inside said firstquadrifilar helix.
 12. The antenna of claim 11, wherein said frequencyband within which said second quadrifilar helix is operable is greaterthan said frequency band within which said first quadrifilar helix isoperable.
 13. The antenna of claim 12, wherein said first quadrifilarhelix is utilized to transmit signals during a satellite mode ofoperation.
 14. The antenna of claim 12, wherein said second quadrifilarhelix is utilized to receive signals during a satellite mode ofoperation.
 15. The antenna of claim 8, wherein the radius of said firstquadrifilar helix is greater than the radius of said second quadrifilarhelix.
 16. The antenna of claim 8, wherein one of said first and secondquadrifilar helices is fed with a different circular mode so that saidantenna is operable in a monopole mode within a third frequency band.17. The antenna of claim 8, wherein one of said first and secondquadrifilar helices is fed with a different circular mode and the otherof said helices acts as a parasitic element so that said antenna isoperable in a monopole mode within a third frequency band.
 18. Theantenna of claim 17, wherein said conductive elements of said drivenquadrifilar helix are fed in phase.
 19. The antenna of claim 8, saidquadrature feed network further comprising a balanced 90° branchlinecoupler connected to said first and second quadrifilar helices.
 20. Theantenna of claim 8, said first and second quadrifilar helices furthercomprising a dielectric film with a metallized pattern formed on eachside thereof, said film being wrapped and fixed in a cylindrical shape.21. The antenna of claim 8, said quadrature feed network furthercomprising a third feedpoint for a third frequency band.
 22. The antennaof claim 1, said quadrature feed network further comprising a dummy loadacross said second feedpoint to terminate the balancing of said couplingelement thereacross when a signal is provided to said first feedpoint.23. The antenna of claim 1, said quadrature feed network furthercomprising a short circuit across said first and second feedpoints tocreate an unbalanced condition for said coupling element when a signalis provided to said second feedpoint.
 24. An antenna for transmittingand receiving signals within a first frequency band and a secondfrequency band, comprising:(a) a flexible sheet of film having a firstside and a second side; (b) a first metallized pattern formed on saidfirst side of said film sheet including a plurality of spiral armsconnected to a coupler; and (c) a second metallized pattern formed onsaid second side of said film sheet including a plurality of spiral armsconnected to a coupler;wherein said film sheet is formed into acylindrical tube having a longitudinal axis therethrough so that a firstcoaxial quadrifilar helix is constructed by said spiral arms of saidfirst metallized pattern and a second coaxial quadrifilar helix isconstructed by said spiral arms of said second metallized pattern, saidfirst and second quadrifilar helices being wound in opposite directionswith respect to said longitudinal axis to avoid electromagnetic couplingtherebetween.
 25. The antenna of claim 24, wherein said first and secondquadrifilar helices are conductively coupled to provide opposite sensecircular polarization in said first and second frequency bands.
 26. Theantenna of claim 24, wherein said film sheet is made of a dielectricmaterial.
 27. The antenna of claim 24, wherein the lengths of saidspiral arms of said first quadrifilar helix are greater than the lengthsof said spiral arms of said second quadrifilar helix.
 28. The antenna ofclaim 24, wherein said second quadrifilar helix is positionedconcentrically inside said first quadrifilar helix.
 29. The antenna ofclaim 28, wherein said first quadrifilar helix is utilized to transmitsignals during a satellite mode of operation.
 30. The antenna of claim28, wherein said second quadrifilar helix is utilized to receive signalsduring a satellite mode of operation.
 31. The antenna of claim 24,wherein the radius of said first quadrifilar helix is greater than theradius of said second quadrifilar helix.
 32. The antenna of claim 24,wherein one of said first and second quadrifilar helices is fed with adifferent circular mode so that said antenna is operable in a monopolemode within a designated frequency band.
 33. The antenna of claim 24,further comprising a quadrature feed network connected to said first andsecond quadrifilar helices.
 34. In a portable phone having RF circuitrycontained within a main housing for operating said portable phone inboth cellular and satellite modes, an antenna assembly comprising:(a) abase member connected to a top portion of said portable phone mainhousing; and (b) a radome member rotatably connected to said basemember, said radome member containing a printed antenna therein which isable to transmit and receive signals in said cellular and satellitemodes of operation.
 35. The antenna assembly of claim 34, furthercomprising a hinge member connected to said radome member which isrotatably engaged to said base member, wherein said radome member isrotatable about an axis between a first position adjacent a side surfaceof said main housing and a second position.
 36. The antenna assembly ofclaim 35, further comprising an elbow member connected to said hingemember at a first end and connected to said radome member at a secondend.
 37. The antenna assembly of claim 36, wherein said radome member isoriented substantially perpendicular to said hinge member.
 38. Theantenna assembly of claim 36, wherein said antenna assembly issubstantially L-shaped.
 39. The antenna assembly of claim 36, furthercomprising a plurality of coaxial cables connected to said printedantenna in said radome member at one end and to corresponding connectorslocated on said main housing at a second end, wherein said printedantenna is connected to said RF circuitry.
 40. The antenna assembly ofclaim 39, said coaxial cables being positioned through said radomemember, said elbow member, said hinge member and said base member. 41.The antenna assembly of claim 36, said elbow member further comprisingan access opening therein and an access cap removably mounted thereto.42. The antenna assembly of claim 35, wherein said radome member islocated at said first position during off and standby modes of saidportable phone.
 43. The antenna assembly of claim 35, wherein saidradome member is located at said second position during transmission andreception of signals.
 44. The antenna assembly of claim 35, said axis ofrotation for said antenna assembly being oriented substantially parallelto a top surface of said main housing.
 45. The antenna assembly of claim34, wherein said base member is detachably mounted to said main housingof said portable phone.
 46. The antenna assembly of claim 34, whereinsaid radome member is shaped substantially as a cylindrical tube. 47.The antenna assembly of claim 34, said printed antenna furthercomprising:(a) a flexible film sheet made of dielectric material havinga first side and a second side; (b) a first metallized pattern appliedto said first side of said flexible film sheet; and (c) a secondmetallized pattern applied to said second side of said flexible filmsheet;wherein at least one quadrifilar helix is formed when saidflexible film sheet is rolled into a cylindrical tube and positionedwithin said radome member.
 48. The antenna assembly of claim 47, whereinsaid first metallized layer includes a first pair of spiral arms andsaid second metallized layer includes a second pair of spiral armsoriented so as to form a quadrifilar helix.
 49. The antenna assembly ofclaim 48, wherein said first and second pairs of spiral arms have alength substantially equivalent to a quarter wavelength of a desiredfrequency of operation.
 50. The antenna assembly of claim 48, whereinsaid first and second pairs of spiral arms have a length substantiallyequivalent to a three-quarter wavelength of a desired frequency ofoperation.
 51. The antenna assembly of claim 48, further comprising acoupler connected to said printed antenna, wherein said printed antennahas a circular polarization when said coupler is balanced and saidprinted antenna has a linear polarization when said coupler isunbalanced.
 52. The antenna assembly of claim 51, said coupler furthercomprising a first port for said quadrifilar helix when in a circularpolarization mode and a second port for said quadrifilar helix when in alinear polarization mode.
 53. The antenna assembly of claim 52, saidcoupler further comprising a dummy load connected to said second port ofsaid coupler so as to terminate the balanced mode of said coupler atsaid second port.
 54. The antenna assembly of claim 52, furthercomprising a short circuit between said first and second metallizedlayers of said printed antenna, said short circuit acting as a feedpointfor said printed antenna when said coupler is in said unbalanced mode.55. The antenna assembly of claim 47, wherein said first metallizedlayer includes a first set of spiral arms to form a first quadrifilarhelix of a first designated radius and said second metallized layerincludes a second set of spiral arms to form a second quadrifilar helixof a second designated radius.
 56. The antenna assembly of claim 55,wherein said spiral arms of said first quadrifilar helix have a lengthgreater than said spiral arms of said second quadrifilar helix.
 57. Theantenna assembly of claim 55, wherein said spiral arms of said firstquadrifilar helix are wound in an opposite direction from said spiralarms of said second quadrifilar helix with respect to a longitudinalaxis of said cylinder tube.
 58. The antenna assembly of claim 55,wherein the radius of said first quadrifilar helix is greater than theradius of said second quadrifilar helix.
 59. The antenna assembly ofclaim 55, wherein said spiral arms of said first quadrifilar helix donot touch said spiral arms of said second quadrifilar helix where theycross.
 60. The antenna assembly of claim 55, said first and secondmetallized patterns further comprising a balanced quadrature branch-linecoupler connecting said printed antenna to a plurality of coaxialcables, wherein a spiral arm from each of said first and secondquadrifilar helices is connected to each leg of said coupler.
 61. Theantenna assembly of claim 60, said printed antenna further comprising aplurality of plated vias in said flexible film sheet so that a spiralarm of said first and second metallized patterns connected to a leg ofsaid coupler is able to branch off, extend through one of said platedvias, and provide a spiral arm on the opposite metallized pattern. 62.The antenna assembly of claim 60, said coupler providing a first portfor said first quadrifilar helix and a second port for said secondquadrifilar helix.
 63. The antenna assembly of claim 62, furthercomprising an open circuit in one of said first and second coupler portsso that said printed antenna operates with a linear polarization when afrequency is provided thereto.
 64. The antenna assembly of claim 63,wherein the quadrifilar helix associated with the coupler port in whichsaid open circuit is not provided acts as a parasitic element.
 65. Theantenna assembly of claim 60, wherein said printed antenna operates witha circular polarization when said coupler is in a balanced mode.
 66. Theantenna assembly of claim 60, wherein said printed antenna operates witha linear polarization when said coupler is in an unbalanced mode. 67.The antenna assembly of claim 55, wherein said first quadrifilar helixis adapted for a signal frequency less than said second quadrifilarhelix.
 68. A quadrifilar helix antenna, comprising:(a) a flexible sheetof dielectric film; (b) a first pair and a second pair of conductivearms printed upon said flexible sheet of dielectric film in such mannerthat said conductive arms form a quadrifilar helix when said flexiblesheet is rolled into a cylindrical tube; and (c) a balanced 90° branchline coupler printed on said flexible sheet of dielectric film, whereinsaid coupler is able to provide two balanced output signals in phasequadrature relative to each other, said coupler further comprising:(1) afirst output port connected to said first pair of conductive arms, saidfirst output port having a first terminal for providing an in-phaseportion of a first output signal to one of said first pair of conductivearms and a second terminal for providing an anti-phase portion of saidfirst output signal to the other of said first pair of conductive arms;(2) a second output port connected to said second pair of conductivearms, said second output port having a first terminal for providing anin-phase portion of a second output signal to one of said second pair ofconductive arms and a second terminal for providing an anti-phaseportion of said second output signal to the other of said second pair ofconductive arms; and (3) at least one input port for receiving an inputsignal and splitting said input signal between said first and secondpairs of conductive arms in relative phase progression so as to beradiated with circular wave polarization.
 69. The quadrifilar helixantenna of claim 68, wherein said first pair of conductive arms are indiametrically opposed relation and said second pair of arms are indiametrically opposed relation.
 70. The quadrifilar helix antenna ofclaim 69, wherein said first pair of conductive arms and said secondpair of conductive arms are interposed at approximately 90° with respectto each other.
 71. The quadrifilar helix antenna of claim 68, whereinone of said first pair and one of said second pair of conductive arms ispositioned on a first surface of said flexible sheet and the other ofsaid first and second pairs of conductive arms is positioned on a secondsurface of said flexible sheet.
 72. The quadrifilar helix antenna ofclaim 68, wherein said coupler has a second input port which isunbalanced so that an input signal provided thereto is split betweensaid conductive arms in a manner so as to be radiated with a linear wavepolarization.